Raker control



Jan. 3, 1956 H, R, KN|TT| E 2,729,175

RAKER CONTROL "f Filed Nov. 1, 195o 2 sheets-sheet 1 ATTDRN EYB H. R.KNITTLE RAKER CONTROL Jan. 3, 1956 2 Sheets-Sheet 2 Filed Nov. l, 1950ATTCI RNEYS United States Patent O RAKER CONTROL Harry R. Knittle,Catawissa, Pa. Application November 1, 1950, Serial No. 193,350 1 Claim.(Cl. 11G-32) This invention relates to a coal-red furnace, and moreparticularly to a thermostatically-controlled grate for the furnace.

The object of the invention is to provide an automatic,thermostatically-controlled mechanism for disconnecting the operation ofa furnace grate when the hot coals in the iire box reach the grate andwhich startsV the operation of the grate when an ash bed iills up on thegrate whereby the ashes fall into the ash pit.

Another object of the invention is to provide a mechanism that will stopthe agitation of the grate when the hot coals in the lire box approachthe grate to thereby eliminate the waste of fuel and increase the firebox eliiciency.

Still another object of the invention is to provide a mechanism whichwill allow agitation ofthe grate when an excess of ashes accumulate inthe fire box, the mechanism being adjustable so that the mechanism canbe set to operate within a predetermined temperature range, if de`sired.

A further object of the invention is to provide a gratecontrol mechanismwhich is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings forming a part of this application, and inwhich like numerals are used to designate like parts throughout thesame:

Figure 1 is a side elevational view of a conventional iire box havingthe mechanism of the present invention installed thereon, and in alocking position;

Figure 2 is a fragmentary side elevational view of the grate-actuatingmechanism in an unlocked position;

Figure 3 is an enlarged vertical sectional view taken at an angle of 90from the views shown in Figures 1 and 2, and illustrating thethermostatic control for the mechamsm;

Figure 4 is a View similar to Figure 3, but showing the parts in alocked position;

Figure 5 is a fragmentary projection of Figure 4, illus trating thegrate arm movement in an unlocked position;

Figure 6 is a sectional View showing the manually operable means foradjusting the mechanism.

Referring in detail to the drawings,the numeral 10 designates aconventional furnace which is provided with a re box 11, Figure 1, andarranged in the bottom of the fire box 11 is the usual movable grate 12.The grate 12 is mounted on rollers or wheels 14, so that the grate 12can be readily agitated or reciprocated back and forth to thereby emptythe ashes that accumulate therein. For conveying coal to be burned froma suitable bin (not shown) to the tire box 11, an inclined conveyor tube15 is provided. The conveyor tube 15 has a gravity feed discharge chuteconnected to its upper end so that the coal will be directed into thefire box 11. A motor 17 is provided for rotating the conveyor tube 15.The motor 17 is supported on a bracket 18 which may be secured to theoutside of the furnace 10, and the motor 17 serves to drive an endlessbelt 19. The belt 19, ate a gear box 20, and the gear a small gear 21.The gear 21 is gagement with a large gear 22, and the gear 22 is securedto the conveyor tube 15. Thus, upon energization or actuation of themotor 17, the conveyor tube 15 will be rotated so that coal can beconveyed from a suitable bin or reservoir upwardly, then through thedischarge chute 16 and into the re box 11.

Secured to the exterior of the furnace 10 is a support member 23, and apin 24 pivotally connects a counterweight or actuating or controller bar25 to the support member 23. Projecting from the raker bar 25 andsecured thereto or formed integrally therewith is an arm 26. It will benoted from Figures l and 2 of the drawings, that the arm 26 is arrangedangularly with respect to the controller bar 25. Rotatably supported bythe arm 26 is a wheel 27, and the wheel 27 is adapted to be selectivelyengaged by or contacted by a cam 28 which is secured to the exterior ofthe conveyor tube 15. The gear box 20 is secured to and supported on abracket 29, and the bracket 29 is secured to the exterior of the furnace10.

Figure 1, serves to operbox 20 serves to rotate arranged in meshing en-A pin 30 pivotally connects a link 31 to the arm 26, and au L-shapedelement 33 has one end pivotally connected to the other end of the link31 by a pin 32. The connecting element 33 serves to rotate a drivenshaft 34. A connecting rod 35 (broken lines in Figure l) has one endpivotally connected to the link 31 by a pin 32, While the other end ofthe connecting rod 3S is pivotally connected to the grate 12 by a pin36.

The numeral 37 designates one of the vertical walls of the furnace 10,Figure 3, and the wall 37 is provided with an opening 38. Secured to thewall 37 is a bracket 39, the bracket 39 being arranged contiguous to theopening 38, and the bracket 39 being secured to the wall 37 by suitablesecuring elements, such as bolts or screws 40. Projecting inwardly fromthe bracket 39 and extending into the furnace 10 is an ear or arm 41. Athermal unit or thermostat 42 in the shape of a spiral or coil has oneend connected to the inner end of the ear 41 by a suitable securingelement, such as a rivet 43. The thermostat 42 is adapted to expand orcontract, depending upon the temperature conditions Within the furnace.

Extending from the other side of the bracket 39 and secured thereto orformed integrally therewith is an ear or arm 44. A lever 45 is provided,and the lever 45 includes an upper section 46 which is provided with aninclined surface 47 for a purpose to be later described. The uppersection 46 is pivotally connected to a lower section 48 by means of apin 49, there being a pivot pin 50 pivotally connecting the lowersection 48 to the outer end of the ear 44;

A spring member 51 has one end connected to the lower section 48 by arivet or screw 52, while the other end of the spring member 51 isconnected to the upper section 46 by a rivet or screw 53.

Connected to the free end of the thermostat 42 is a tube 54. The tube 54is hollow and is connected to the thermostat 42 by a rivet or screw 55.Mounted for telescopic movement into and out of the tube 54 is a stem56, and the stem 56 has itsl outer end connected to the lower section 48by a pivot pin 57. The stem 56 is provided with a threaded portion 58for a purpose to be later described. The tube 54 extends through anopening 59 in the bracket 39.

For moving the stem 56, a knurled knob 60 is provided. The knurled knob60 includes an annular collar 61 which rides in a slot 62 that is formedin a clip 63. The clip 63 is secured to the tube 54 by suitable securingelements, such as rivets or screws 64. Thus, by rotating the knurledknob 60, the stem 56 can be adjusted or moved In use, the motor 1-7-isactuated-to drive the belt 19, and the gearbox 2), whereby nthe-gear-Zlrotates. "Since the gear 21 meshes with`th`e gear v22, `theconveyortu'be will berotate'd' so'tha't coal willbe -conveyed from a binupwardly into the dischargechute 16 and then-into the lire box"1'1.Normally/,the coal falls onto the, grate 12, andthe grate "-12isconstantly being agitated so that the ashes will vtumble off vthroughYthegratc '17. into any suitable receptacle. This agitation'f the ,grate1'2 is brought about as follows: The conveyor tube rotates, whereby thecam'28 selectively engages-the wheel `r217 so that mclink/31 is-moved'downwardly elevating the weight ar1n`26 and upon continuousl travelvofthe -cam vthe weight arm 26 returns theroller l27,prov'iding a backan'dfiorth movement. This movement of the link 31 causes oscillation ofa driven shaft Slwhich'is' located within the furnace lll, and theconnecting to move back and k.forth so that accumulated ashes will beemptied from Athe grate. n

lt w'illbe seen from' the drawings that the Aback-andforth `movement ofthe'link 51is caused only whenthe temperature -in the vicinity'fthevgra'te is not too hig'h. That is, if the coals'have not workedthemselves down onto the grate 1-2, the-grate 12 will be continuouslyagitated, and Figures )2, 3 and f5 showftheposition ofthe parts when thegrate is'being agitated. Thus, 'if there is no excessivelyhightemperature in the vicinity of Vthe'thermostat 42, the thermostat"'42 will be inits contractedI position, so that the uppersection 46 'ofthe Vlever Y45 will be pivoted out lof the way of the controller-bar2'5, whereby the controller bar will be free to -pivot as the camVZSengages the wheel 27. "When hot coals are on the grate I2, the grate I2will stop moving, so that there will be no wastage of hot coals or fuel.Thus, when the temperature of the grate`12 gets tooV high, thethermostat 42 expands to causethe tube f54 and the stem56 to move sothat the lever`45 'will move into the'Figures l and`4 position.Therefore, the controller bar -25 will'be unable to pivot, and the wheel27 will be arranged sufficiently spaced from 'the cam'28 so that the cam28'will not engage the wheel 27, whereby 'the grate '12 will not beagitated until the temperature in the vicinity of the thermostat 42again drops.

The element 33 may'have a suitable ratchet Wheel connected thereto. Anas'hpit is arranged'below the traveling grate l2. Thetemperature-actuated element may `be constructed sothat either a rotaryor rectilinear motion may be imparted-'to the shaft to -which `it isconnected. -T-he assembly of the present invention can-be readilyattached to existing furnaces without materially changingfthe furnaces.There are no electrical circuits which area potentialsourc'eof'trou'ble. Also, none of the .parts comes into Contact with thelire in the'furnace, so that they are not subject to being burned out.The assembly needs no power vto operate, and the assembly canbe suppliedas a control for-new vfurnaces,-or can be sold to owners -of furnacesnow in use, where the ,present control is not satisfactory, The assemblyof theypresent-invention is of simple construction, positive in action,-and will have or rod -causes the grate Y12 f cause a minimum amount oftrouble or maintenance.

is sufciently low, the pivoted lever will be moved away from engagementwith the controller bar 25, so that the controller bar will be free tomove whereby the grate 12 will be agitated. This agitation of the grate12 will cause the ashes to be emptied or removed so that the fire or hotcoals will move cl'osertoV the grate, thereby increasing the temperatureofthe :grate and ofthe ash pit. When this temperature gets sufficientlyhigh, the thermostat 42 reverses or contracts, fs'o /thatthe uppersection 46 of the lever 45 moves back yinto engagement with thecontroller`bar'25. `It willbe noted that the lever4'5 is 'pivoted at 49,and the spring-member Sliconnects the upper and lower sections of thelever 45 together. This spring member 51, together with the tapered orinclined surface 47, allows the controller bar 2S to return to itsnon-operating ,position when the lever45 has -beenpulled into engagementl-befo're Ythe controller bar '.ZS'has returned to 4that position. "Thespring v5'1 then'forces the lever 4S'backinto engagement. Thetemperature at which the instrument operates caribe yadjusted bychanging the length Vof the tube5'4 and stem 5'6rby means of the knurled4knob 60.

`I claim:

In combination with a'furnace, a reciprocable grate, a bracket mountedon a wllof the furnace, said bracket having arms extending from 'bothsides thereof and positioned with one arm extending into the furnaceupon which the bracketis mounted, and the other extending outwardlyhfromthe furnace, a thermostat carried'by the arm extendinginto t'he'furnaceand positioned to be located below the grate, a vertically disposedlever pivotally mounted'on the armextending'outwardly from the furnace,power ydrive mechanism, linkage between said mechanism and lgrate toreciprocate 'the latter, a movable controller'bar movable in onepositionto disengage the drive mechanism 'from thelirikage, the verticallydisposed lever having airadjustable connecting lbetween its lower endand-'the 'thermostat in the furnace, the upper end of the lever having a'knee action joint therein with resilient means for resilientlyretaining the parts in alignment, the upper end of the levery being vinalignment with the controller bar when Athe thermostat is inihotposition to disengage the drivemechanism, Iand 'out of alignmenttherewith on the cool position of the thermostat to 'permit engagementof the drive and reciprocation of the grate.

4-RererencesCited inthe'le of this patent VUNITED STATES yPATENTS

